The invention relates generally to a method for improving the surface characteristics of barrier layers that are used in semiconductor processing.
Submicron, straight walled contacts with high aspect ratios (i.e., ratio of depth to width &gt;2) may be metallized with the use of collimated Ti/TiN PVD (Physical Vapor Deposition) technologies, followed by CVD-W (Chemical Vapor Deposition with tungsten), PVD Al/reflow or cold/hot PVD Al to completely fill the contacts. However, at these high aspect ratios, obtaining effective flow of the deposited material into the contact holes can present some difficulties. In the past, effective reflow or diffusion of the deposited metals into the holes was achieved by using higher process temperatures and/or longer process times. It is desirable, however, to find other ways of achieving these objectives without having to use higher process temperatures or longer process times. The invention addresses this need.